Heart Gene Therapy Improved

For the first time, doctors have injected genetically engineered DNA into heart muscles by using a catheter without any anesthesia. The therapy helps restore blood flow to clogged arteries

Until now, the gene was injected into the heart during a two-hour surgery that required general anesthesia and several days of recuperation.

The new, minimally invasive technique will eventually allow patients to go home an hour after it's completed, said Dr. Jeffrey Isner, chief of cardiovascular research at St. Elizabeth's Medical Center in Boston. It could be a safer alternative to bypass surgery or angioplasty for high-risk patients.

Isner performed the procedure in about 30 minutes Tuesday on Sam Hart, 81, of Rome, N.Y. The early results have been encouraging to Hart, who underwent bypass surgery and an angioplasty operation, but has continued to have heart problems.

"I felt like someone who was waiting for the electric chair, and just found out I was going to be free," Hart said.

In the new method, a catheter is inserted in the groin and directed to the heart by X-ray imaging. A needle is advanced out of the catheter and injects the DNA into the inner wall of the heart. That leads to production of the protein vascular endothelial growth factor, which stimulates the growth of new blood vessels.

Dr. Nicholas Kipshidize, an assistant professor at the Medical College of Wisconsin, said it's too early to tell whether the catheter method will he widely used.

"We still don't know the overall success of this procedure," he said.

Researchers have two main concerns about the gene therapy. They fear it could nourish the blood supply of undetected cancers, causing tumor growth, and cause overgrowth of vessels in tissues such as the retina of the eye.

Isner said retinal specialists found no changes in the eyes of about 60 diabetic patients who received the gene therapy through the traditional surgical procedure.

He added that there hadn't been a long enough follow-up to determine the risk of tumor growth, though no new tumors have been seen in patients, and animal data suggests the therapy isn't likely to develop tumors.